Safety manhole for sewers



Aug. 11, 1925.

INVENTOR ATTORNEY A. M. KHUN SAFETY MANHOLE FOR SEWERS Filed Oct. 2, 1924 Patented Aug.

ALBERT M. KHUN, OF ELIZABETH, NEWJERSEY.

SAFETY IVIAINHOLE FOR SEWERS.

Application filed October 2, 1924. Serial No. 741,206.

To all whom it may concern:

Be it known that I, ALBERT M. KHUN,

a citizen of the the city of Elizabeth, lave invented a Safety Manholes In cases of freshets or of accidental page of sewers the water often flows through the manholes m city streets, flooding the streets.

filth which enda citizens. The

United States,

residing in State of New Jersey,

certain Improvement in for Sewers, of which the following is a specification.

stopback This causes a deposit of ngers the health of the present invention has for its object the provlsion of means whereby the reflux of sewage upward through street manholes may be automatically prevented. The

means employed have been found thoroughly practical and installed and tions which may are easily manufactured do not offer any PTLOJGC- catch dirt and offensive matter in any manner.

The invention is shown 111 a preferred form in the accom panying drawings, wherein Figure 1 1s a vertlcal sectional View of a manhole supplied with the safety valve, and Flgure 2 1s a vertical sectional View of the same Figure 1.

latter is fastened ner upon the seat 12 The usual manhole gr a short flaring tubular at right angles to the view in ating 10, rests upon castmg 11, which down in any suitable manleading down to the sewer below.

at the top of the pipe There is preferably secured under the casting 11, a ring 13 of suitable metal to provlde a seat for the ball hereinafter described.

The seat for this ball may be provided in any desired way, and not necessarily by the use of the separate ring 13.

The top section of the pipe leading down to the sewer under the manhole is gradually widened from left to right in Figure 1, and narrows again to form the seat 12. This side just described 16 to right and much less prono enlargement forms a side chamber 14 for there is also a swelling left in Figure 2 which is unced in character.

This

swelling has its origin at'the bottom along lines 17 on opposite sides, whereby two parallel inclined ridges or tracks are formed. Upon these the ball 15 rests, and under ordinary circumstances, gravity keeps this ball at the lower end of the tracks 17, so that it occupies the chamber 14, and is entirely out of the path of liquids dropping down through the grating 1.0.

The ball 15 may be made in any well known manner to render it fioata-ble, and is of such a size that it will fit against the ring 13 or its equivalent to close the opening of the manhole when brought into the position shown in dotted lines. The con.- sequence is that, if the water should back up so as to threaten to overflow the manhole, it would raise the ball 15, causing it to roll along the inclined top of the side chamber 1 1-, until it was forced against the ring 18 or other valve seat, thereby stopping the opening and preventing overflow.

On the subsidence of the water level, and return of normal conditions, gravity would cause the ball to return to the position shown in the drawing, where it is entirely out of the path of any material dropping into the sewer.

What I claim is- In a street manhole construction, a substantially upright sewer pipe having an enlarged top section provided with an annular recess, a side pocket formed on said top section, inclined guide-ways in the side walls of said section and said pock t terminating with their lower ends in said pocket, a removable annular valve seat in said recess above the guideways, a grating recep tacle resting on said valve seat and adapted to receive a manhole grating, means adapt-- ed to seal the valve seat and the receptacle in said annular recess, and a buoyant ball adapted to roll on the guideways to lodge in said pocket or rise to close the valve seat actuated by liquid in the sewer pipe.

In testimony whereof I have hereto set my hand on this 25th day of September 1924. 

